Examining a Decade of ARM Research in the Topical Western Pacific


Department of Energy researchers at Pacific Northwest National Laboratory led a team to investigate the scientific utility of atmospheric data collected by the Atmospheric Radiation Measurement (ARM) scientific user facility over a decade of observations in the equatorial tropical western Pacific (TWP), an
important climatic region. Strong solar heating, warm sea surface temperatures, and the annual progression of the Intertropical Convergence Zone (ITCZ) across this region generate abundant convective systems that have a profound impact on global climate and precipitation. To accurately evaluate tropical cloud systems in models, measurements are needed of tropical clouds, the environment in which they reside, and their impact on the radiation and water
budgets. Because of the remote location, ground-based datasets of cloud, atmosphere, and radiation properties from the TWP region traditionally came primarily from short-term field experiments. However, these short-term datasets provided only limited statistical and climatological information. To provide long-term measurements of the surface radiation budget in the tropics and the atmospheric and cloud properties that affect it, ARM established the TWP measurement sites in 1996. This analysis gives examples of the wide range of scientific use of these unique long-term datasets, including characterization of cloud properties, analysis of cloud radiative forcing, model studies of tropical clouds and processes, and validation of satellite algorithms. The impact of recently installed instrumentation on new opportunities for tropical atmospheric science is also discussed. The study highlights contributions of ARM TWP data to increased knowledge of tropical cloud systems and the tropical surface radiation budget.


Long, C. N., S. A. McFarlane, A. Del Genio, P. Minnis, J. Mather, J. Comstock, J. Mace, M. Jensen, C. Jakob, and T. P. Ackerman. 2012. “ARM Research in the Equatorial Western Pacific: A Decade and Counting,” Bulletin of the American Meteorological Society, DOI: 10.1175/BAMS-D-11-00137.